JP7395870B2 - axial gap motor - Google Patents

Description

The present disclosure relates to axial gap motors.

An axial gap motor includes a gap between a stator and a rotor in which a rotating magnetic flux is formed in the direction of the motor's rotation axis. Since the core of these axial gap motors can be made large, it is easy to construct a thin motor with a large output torque. , which was difficult compared to radial gap motors. In a radial gap motor, the core and back yoke can be easily formed by laminating electromagnetic steel plates of the same shape in the thickness direction, whereas in an axial gap motor, the core is formed by laminating the core and back yoke in the thickness direction from the back yoke. This is because it has a protruding shape and cannot be manufactured by laminating electromagnetic steel sheets of the same shape. For this reason, conventionally, the back yoke and the core are manufactured separately and then joined together to form the stator (for example, see Patent Document 1).

In Patent Document 1, a hole into which a core (teeth) fits is provided in the back yoke, and the core is inserted into the hole, and the core and the back yoke are bonded by fixing with a coating agent of an electromagnetic steel plate or fixing with an adhesive. , or by welding.

JP2009-296825A

However, in an axial gap motor, when the rotor is rotated by a rotating magnetic field, the reaction force of the torque that rotates the rotor acts as a force in the circumferential direction on the core on the stator side. A large force will be applied to the joint between the back yoke and the back yoke. Therefore, in the configuration of Patent Document 1, there is a risk that the stator may be damaged.

The present disclosure can be realized as the following forms or application examples. That is, an axial gap motor according to the present disclosure includes a rotating rotor, and a stator that faces the rotor and is disposed with a gap in a first direction parallel to the axis of rotation, and the stator includes: A core in which thin plates through which magnetic flux passes are laminated along a second direction perpendicular to the first direction, and an annular yoke having the core, the core having a plurality of independent fitting parts separated from each other. The plurality of fitting portions for each core are fitted into a plurality of attachment portions formed on the yoke itself in correspondence with the plurality of fitting portions.

FIG. 1 is a schematic configuration diagram showing a schematic configuration of an axial gap motor according to a first embodiment in a cross-sectional view. FIG. 3 is a perspective view illustrating the shape of a stator. FIG. 3 is an explanatory diagram showing the attachment relationship between one core and yoke that constitute the stator. FIG. 3 is an explanatory diagram illustrating the attachment relationship of the coil to the core. FIG. 3 is a plan view schematically showing the shape of the core when viewed toward the yoke. FIG. 7 is an explanatory diagram illustrating a case where a groove-shaped attachment portion having a predetermined length is provided from the inner circumferential side to the outer circumferential side of the yoke. FIG. 7 is an explanatory diagram illustrating a case where a groove-shaped attachment portion having a predetermined length is provided from the outer circumferential side to the inner circumferential side of the yoke. FIG. 7 is an explanatory diagram illustrating a case where a mounting portion is provided as an opening with the width direction as the longitudinal direction approximately at the center of the yoke in the width direction. FIG. 3 is an explanatory diagram illustrating the forms of two types of cores and the shapes of electromagnetic steel sheets to be laminated. FIG. 7 is an explanatory diagram showing other forms of the core. Explanatory drawing showing the shape of a yoke and a mounting part used in other stators. FIG. 10 is an explanatory diagram illustrating the shape of a core attached to the yoke shown in FIG. 9 and the shape of an electromagnetic steel plate forming the core. FIG. 7 is a plan view showing a part of a stator according to another embodiment. Furthermore, the top view which shows a part of stator which is another embodiment. FIG. 7 is a perspective view showing a part of the stator of the second embodiment. FIG. 7 is a perspective view showing a state in which the core of the second embodiment is attached to a yoke. FIG. 7 is an explanatory diagram showing a part of the stator of the second embodiment as viewed from above. FIG. 6 is an explanatory diagram showing the configuration of a stator according to another embodiment. FIG. 7 is an explanatory diagram showing the configuration of a stator according to still another embodiment. FIG. 7 is an explanatory diagram showing the configuration of a stator according to still another embodiment. FIG. 7 is an explanatory diagram showing the configuration of a stator according to still another embodiment. FIG. 3 is an explanatory diagram illustrating the lamination direction of electromagnetic steel sheets of a yoke and a core. FIG. 2 is an explanatory diagram showing a case where electromagnetic steel sheets are laminated along the radial direction. FIG. 2 is an explanatory diagram showing a case where electromagnetic steel plates are laminated along the circumferential direction.

A. First aspect:
(1) First embodiment:
FIG. 1 is a schematic cross-sectional view showing the schematic structure of an axial gap motor 20 according to the first embodiment. This axial gap motor 20 includes a rotor 40 at the axial center of a rotating shaft 21, and has a so-called double-staff structure in which stators 31 and 32 are provided on both sides of the rotor 40 in the axial direction. As illustrated, the upward axial direction of the rotating shaft 21 is indicated by the symbol A, and the outward direction in the radial direction with respect to the rotating shaft 21 is indicated by the symbol R, respectively. The directions indicated by the symbols A and R are similarly indicated in other figures. The direction indicated by symbol A is sometimes referred to as the axial direction, and the direction indicated by symbol R is sometimes referred to as the radial direction. In addition to these directions, the circumferential direction of the rotor 40 and the stators 31 and 32 may also be illustrated as C. If the direction of the axial direction A is a first direction, the directions of the radial direction R and the circumferential direction C correspond to a second direction orthogonal to the first direction.

Although the rotating shaft 21 is shown as a cylindrical body in FIG. 1, it may be a hollow rotating shaft. In the axial gap motor 20, the thickness in the rotation axis direction A tends to become thinner and the dimension in the radial direction R tends to increase. It is also desirable to adopt a configuration in which wiring is passed through.

The rotor 40, which is fixed approximately at the axial center of the rotating shaft 21, has a plurality of permanent magnets 41, 43 arranged evenly in the circumferential direction, 12 in this embodiment, near the end of the rotor 40 in the radial direction R. are doing. The number and arrangement of the permanent magnets 41 and 43 are determined by the number of phases and the number of poles of the axial gap motor 20. A fixed part 45 to which the rotating shaft 21 is fixed is formed in the center of the rotor 40, and the rotating shaft 21 is press-fitted into the fixed part 45 and fixed. Of course, both may be coupled by a key and a keyway.

The stators 31 and 32 are attached to the fixed portion 45 of the rotor 40 via bearings 23 and 24. The rotating shaft 21 and rotor 40 are rotatably held by the bearings 23 and 24 with respect to a motor case in which the stators 31 and 32 are connected by a side case 27. The stators 31 and 32 are provided with stator cores (hereinafter simply referred to as cores) 51 and 52 so as to face the permanent magnets 41 and 43 of the rotor 40. A schematic configuration of the stator 31 is shown in the perspective view of FIG. Since the axial gap motor 20 of this embodiment has a three-phase, four-slot configuration, the number of cores 51 per stator 31 is twelve.

The stator 31 is made up of 12 cores 51, a back yoke (hereinafter simply referred to as yoke) 35 provided in common to these cores 51, and a coil 61 that is a winding wound around the outer periphery of each core 51. Become. The yoke 35 is constructed by laminating annular, ie, donut-shaped, electromagnetic steel plates having a width that is substantially the same as the radial width of the core 51, and has a predetermined thickness. An insulating film is formed on the surface of the electromagnetic steel sheets, and after lamination, each electromagnetic steel sheet is fixed by melting the insulating film. Note that the laminated electromagnetic steel plates may be joined by applying an adhesive or by welding. The joining of electromagnetic steel plates is the same for the core described later.

The coil 61 surrounding the outer periphery of the core 51 may be wound around the core 51 individually, or may be wound into a bobbin shape in advance and fitted onto the outer periphery of the core 51. The other stator 32 similarly includes twelve cores 52, a yoke 36 common to these cores 52, and a coil 63 wound around the outer periphery of each core 52. Twelve coils 61 attached to twelve cores 51 constitute a three-phase, four-pole winding. The two stators 31 and 32 have a plane-symmetrical structure with the rotor 40 in between. Twelve permanent magnets 41 and 43 provided on the rotor 40 and the cores 51 and 52 face each other with a gap of a predetermined distance along the axial direction A, which is the first direction.

Next, the configuration of the core 51 and the attachment of the core 51 and the yoke 35 in the first embodiment will be described. FIG. 3 is an explanatory diagram showing the attachment relationship between one core 51 and the yoke 35 that constitute the stator 31. As illustrated, the core 51 of this embodiment is constructed by laminating a plurality of thin electromagnetic steel sheets 71. Each electromagnetic steel sheet 71 has the same shape, and has convex fitting portions 72 and 73 on both sides of the lower end of a rectangular shape when viewed from the front. Therefore, the core 51 in which a plurality of electromagnetic steel plates 71 are laminated has a rectangular parallelepiped shape as a whole, and the fitting portions 72 and 73 are also continuous, and two rectangular parallelepiped protrusions are formed on both sides of the lower end of the core 51. form a section. Since the electromagnetic steel sheet 71 is not used alone, the "fitting part" refers to the convex-shaped part when describing one electromagnetic steel sheet 71, and the explanation will be made with the electromagnetic steel sheets 71 stacked together. "time" refers to the entire rectangular parallelepiped-shaped portion at the lower end of the core 51.

The yoke 35 to which the core 51 is attached is provided with groove-shaped attachment portions 81 and 82 having a predetermined length from the inner peripheral side of the yoke 35, corresponding to the fitting portions 72 and 73 of the core 51. The sizes of the mounting parts 81 and 82 of the yoke 35 are equal to the sizes of the fitting parts 72 and 73 of the core 51, so the fitting parts 72 and 73 of the core 51 are fitted into the mounting parts 81 and 82 of the yoke 35. This allows the core 51 to be fixed to the yoke 35. That is, the fitting parts 72 and 73 of the core 51 fit into the attachment parts 81 and 82 of the yoke 35. The position where the fitting parts 72 and 73 are attached to the attachment parts 81 and 82 and the core 51 is fixed to the yoke 35 is the core fixing position. FIG. 4 shows a state in which the core 51 is fixed at a fixed position. The core 51 and the yoke 35 may be fixed by press-fitting the fitting parts 72, 73 into the mounting parts 81, 82, or may be fixed by adhesive or welding. The stator 31 is assembled by fitting the coil 61 into the core 51 in the state shown in FIG. 4 .

FIG. 5 is a plan view schematically showing the shape of this core 51 when viewed toward the yoke 35. As shown in FIG. However, when the core 51 is viewed in plan from the side opposite to the yoke 35, the attachment parts 81 and 82 of the yoke 35 are not normally visible, but in order to clearly show the attachment relationship, the external shapes of the attachment parts 81 and 82 are shown in the figure. The lines are indicated by hidden lines (dashed lines). This also applies to other figures unless otherwise specified. Although the rotation axis direction A, the radial direction R, and the circumferential direction C are shown in FIG. 5, for convenience of illustration, the center A in the rotation axis direction is not drawn at the center position on the figure of the yoke 35. , close to the illustrated area of yoke 35. In the first embodiment and its modifications, the plurality of attachment parts (here, two attachment parts 81 and 82) are provided at positions separated from each other in the circumferential direction C of the yoke 35. In other words, the two attachment parts 81 and 82 are lined up in the circumferential direction C of the yoke 35. A configuration in which the plurality of attachment parts are separated along the radial direction R of the yoke 35 will be described in a second embodiment. The stacking direction of the electromagnetic steel sheets 71 is the radial direction R. A configuration in which the stacking direction of the electromagnetic steel sheets 71 is the circumferential direction C will be described in the section of other embodiments.

Various variations are possible for the positions of the attachment parts 81 and 82. For example, as shown in FIG. 6A, groove-shaped mounting portions 81 and 82 having a predetermined length may be provided from the inner circumferential side of the yoke 35 toward the outer circumferential side, or as shown in FIG. 6B, The groove-shaped mounting portions 83 and 84 may have a predetermined length extending toward the inner circumferential side. Alternatively, as shown in FIG. 6C, mounting portions 85 and 86 may be provided approximately at the center of the yoke 35 in the width direction as openings whose longitudinal direction is the width direction.

According to the first embodiment described above, in the axial gap motor 20, the two fitting parts 72 and 73 of the core 51 are fixed by the two attachment parts 81 and 82 of the yoke 35, so that the rotor 40 can be rotated. Even if a torque reaction force due to the magnetic flux is applied to the core 51 in the circumferential direction, the possibility that the core 51 will come off the yoke 35 or be damaged by shear force can be reduced. Moreover, in this embodiment, since the fitting parts 72 and 73 of all the electromagnetic steel plates 71 receive force in the circumferential direction, the strength against shear force can be further increased. In addition, in this embodiment, the electromagnetic steel plates 71 constituting the core 51 can be of the same shape, and the core 51 can be manufactured easily. In this embodiment, the core 51 can be attached to the yoke 35 by simply inserting the plurality of fitting portions 72 and 73 into the attachment portions 81 and 82, and in this respect, manufacturing of the axial gap motor 20 is facilitated.

Furthermore, in this embodiment, since the fitting parts 72 and 73 and the attachment parts 81 and 82 are provided across the width direction (radial direction R) of the yoke 35, the force applied in the circumferential direction C of the yoke 35 is reduced. Since the receiving area becomes wider, in other words, the load per unit area becomes smaller, the strength against circumferential shear force can be further increased.

Further, in this embodiment, since the magnetic steel plate 71 is used for the core 51, high efficiency is achieved as a core constituting the axial gap motor 20. In the axial gap motor 20, it is known that the core is formed of so-called compacted powder, which is made by hardening magnetic powder under high pressure.In contrast, the core 51 made of laminated magnetic steel plates 71 is They showed high performance, with an output torque of about 10% and an output torque of about 5%. In this embodiment, since the yoke 35 is also made of laminated electromagnetic steel sheets having the same shape, manufacturing is easy and high efficiency is achieved including the yoke.

(2) Other embodiment 1 of the first aspect:
In the axial gap motor 20 of the first embodiment, each of the fitting portions and the attachment portions are provided across the width direction of the yoke 35, and the two fitting portions or the two attachment portions are provided in the circumferential direction of the yoke 35. It is located at a location separated by C. Other embodiments having this configuration will be described below. FIG. 7 is an explanatory diagram showing the form of the core 51A and the core 51a, and the form of the electromagnetic steel sheets to be laminated. In FIG. 7, each electromagnetic steel plate is depicted as a front view as seen in the lamination direction, and the cores 51A and 51a are depicted as a bottom view as seen from the yoke 35 side. The cores 51A, 51a are both formed by laminating two types of electromagnetic steel sheets 711, 712.

In the core 51A, one or more electromagnetic steel plates 712 are laminated on both sides of a plurality of electromagnetic steel plates 711 laminated. The electromagnetic steel sheet 711 has the same shape as the electromagnetic steel sheet 71 of the first embodiment shown in FIG. Therefore, the portion where the electromagnetic steel sheets 711 are stacked has a shape in which fitting portions 72A and 73B protrude from the lower end of the substantially rectangular parallelepiped core 51A. On the other hand, compared to the electromagnetic steel plate 711, the electromagnetic steel plate 712 has a substantially rectangular shape with portions corresponding to the fitting portions 72A and 73A removed. Therefore, there is no protrusion corresponding to the fitting portions 72A, 73A in the layered portion of the electromagnetic steel sheets 712. Even if the core 51A is formed in such a shape, the core 51A has the attachment parts 81 and 82 in the shape shown in FIG. 6A, the attachment parts 83 and 84 in the shape shown in FIG. 6B, and the attachment parts 83 and 84 in the shape shown in FIG. 6C. It can be attached to the shaped attachment portions 85 and 86, respectively.

(3) Other embodiment 2:
In the core 51a, which is another embodiment shown in FIG. 7, a plurality of electromagnetic steel plates 712 are laminated only on one side of a plurality of laminated electromagnetic steel plates 711. In this case, the fitting portions 72A and 73A are formed closer to one side in the radial direction of the core 51a. This core 51a can also be attached to attachment parts 81, 82, etc. in various forms shown in FIGS. 6A to 6C. Note that the cores 51A, 51a may be attached to the attachment portions 81, 82, etc. from the direction facing the surface of the yoke 35, that is, from above in a plan view of the yoke 35, or the cores 51A, 51a may be attached to the attachment portions 81, 82, etc. The mounting portions 81 to 84 may be attached by sliding in the surface direction of the yoke 35 from the outer side of the inner circumference or the outer side of the outer circumference.

(4) Other embodiment 3:
FIG. 8 is an explanatory diagram showing still another form of the core 51B. This core 51B is different in that the core 51, 51A, and 51a described above have a rectangular shape in a plan view, whereas the core 51B has a trapezoidal shape in a plan view. In order for the core 51B to have this shape, it is necessary to make it different from the shapes of all the electromagnetic steel sheets to be laminated. That is, the height of each electromagnetic steel plate is the same, and the width (circumferential length) of the electromagnetic steel plate is larger as the electromagnetic steel plate is located on the outer circumferential side.

FIG. 8 shows, as representative electromagnetic steel sheets constituting the core 51B, an electromagnetic steel plate 721 used at the inner circumferential end of the yoke, an electromagnetic steel plate 722 used at the middle in the stacking direction constituting the core 51B, and an electromagnetic steel plate 722 used at the outer circumferential edge of the yoke. Three electromagnetic steel sheets 723 used in this example are illustrated. As shown in the figure, the electromagnetic steel plates 721, 722, and 723 have different external shapes, but the shapes of the fitting parts 72B, 73B, etc. that are attached to the attachment part on the yoke side are the attachment parts 81 and 723 shown in FIG. 6A. 82, that is, the shape is such that it can be attached to two parallel attachment parts 81 and 82. As a result, in the electromagnetic steel sheet 721, the fitting portions 72B and 73B are provided at both ends of the electromagnetic steel sheet 721, and in the electromagnetic steel sheet 722, the fitting portions 72C and 73C are provided inward from both ends of the electromagnetic steel sheet 722. In the electromagnetic steel plate 723, the fitting portions 72D and 73D are provided further inward from both ends of the electromagnetic steel plate 723. However, the intervals between all the fitting parts are equal.

When the core 51B described above is attached to the yoke 35, the distance between adjacent cores 51B at the inner peripheral end of the yoke 35 and the distance between adjacent cores 51B at the outer peripheral end of the yoke 35 are can be made closer to the same shape than when the plan view shape is rectangular. Therefore, the area of the core 51B attached to the yoke in plan view can be increased, the magnetic force that can be generated when the coil is energized can be strengthened, and the output of the axial gap motor 20 can be increased. In addition, when the core is trapezoidal, it is preferable that the internal shape of the coil attached to the core is trapezoidal to match the core.

(5) Other embodiment 4:
As yet another embodiment, the configuration of a stator 31C including a yoke 35 and a core 51C is illustrated in FIGS. 9 and 10. The core 51C used in the stator 31C of this embodiment is similar in overall shape to the core 51B shown in FIG. 8. That is, when the core 51C is attached to the yoke 35, it has a substantially trapezoidal shape in which the width in the circumferential direction C becomes larger toward the outer circumference of the yoke 35. This core 51C is different from the core 51B shown in FIG. This point is shaped along R.

Therefore, as shown in FIG. 10, the electromagnetic steel plates constituting the core 51C are all different in size and have substantially similar shapes. FIG. 10 shows, as typical electromagnetic steel sheets constituting the core 51C, an electromagnetic steel plate 731 used at the inner circumferential end of the yoke, an electromagnetic steel plate 732 used in the middle in the stacking direction constituting the core 51C, and an electromagnetic steel plate 732 used at the outer circumferential edge of the yoke. Three electromagnetic steel sheets 733 used in this example are illustrated. As shown in the figure, each electromagnetic steel plate 731, 732, 733 has a shape such as a fitting part 72E, 73E attached to the attachment part 81C, 82C on the yoke side, which is attached to the attachment part 81C, 82C shown in FIG. In other words, it has a shape that allows it to be attached to attachment portions 81C and 82C whose spacing gradually increases toward the outside in the radial direction. As a result, the spacing between the fitting portions provided at both ends of each electromagnetic steel sheet is the narrowest between the fitting portions 72E and 73E of the electromagnetic steel sheet 731, and the narrowest between the fitting portions 72F and 73F of the electromagnetic steel sheet 732. In the case of the electromagnetic steel plate 733, the space between the fitting portions 72G and 73G is widest.

The core 51C configured in this manner has a trapezoidal shape in plan view like the core 51B, and can secure a large area on the yoke 35 as the core. Further, the distance between the two attachment parts 81C and 82C becomes wider as the distance approaches the outer circumferential direction of the yoke 35, and when the fitting part of the core 51C is fitted into the attachment parts 81C and 82C from above the yoke 35, the yoke 35 Even if a force is applied in any direction along the surface, the core 51C will not slide off. Moreover, it goes without saying that the same effects as the cores 51, 51A, 51a, and 51B of the other embodiments described above can be achieved.

(6) Other embodiment 5:
FIG. 11 is a plan view showing a part of a stator 31D which is still another embodiment. In this embodiment, the attachment parts 81 and 82 on the yoke 35 side have the same shape as in the first embodiment (see FIG. 6A). On the other hand, although the core 51D has the same outer shape as the first embodiment, the direction in which the electromagnetic steel sheets are laminated is different. That is, in this core 51D, the electromagnetic steel plates are arranged along the circumferential direction C of the yoke 35. This core 51D is therefore composed of electromagnetic steel plates 741 and 742 of two different sizes. A plurality of electromagnetic steel plates 741 are laminated on both sides of the core 51D, and an electromagnetic steel plate 742 smaller than the electromagnetic steel plate 741 is laminated in the central region sandwiched between the electromagnetic steel plates 741. These electromagnetic steel plates 741 and 742 are stacked with their upper sides aligned. Therefore, the core 51D made of laminated and welded electromagnetic steel sheets has the same external shape as the core 51 of the first embodiment, although the lamination direction of the electromagnetic steel sheets is different. In this case, the lower side of the electromagnetic steel plate 741, which is long in the height direction, protrudes to form a fitting part 741, which is attached to the mounting parts 81 and 82.

In the core 51D having this configuration, when a force is applied in the circumferential direction C as the axial gap motor 20, the plurality of electromagnetic steel plates 741 receive that force, so it is difficult to ensure sufficient strength against shearing force. can. Further, since rectangular electromagnetic steel sheets are simply laminated, the electromagnetic steel sheets have the advantage of being easy to process. Furthermore, even if the number of cores is increased or decreased or the circumferential size of the core is changed in design, this can be easily accommodated by simply changing the number of electromagnetic steel plates 742 to be laminated.

(7) Other embodiment 6:
Next, a stator 31E as another embodiment 6 will be described using FIG. 12. In this stator 31E, the stacking direction of the electromagnetic steel plates constituting the core 51E and the configuration of the attachment parts 81 and 82 are the same as in the stator 31D of the other fifth embodiment. This stator 31E differs from the core 51D in that the core 51E has a trapezoidal shape in plan view. Since this core 51E has a trapezoidal shape in plan view, the size of the electromagnetic steel sheets on the outside of the core 51E in the stacking direction gradually becomes smaller. That is, in the core 51E of this embodiment, like the core 51D shown in FIG. A plurality of electromagnetic steel plates 753 whose dimensions gradually become smaller are laminated.

As a result, the core 51E of this embodiment has a trapezoidal shape in plan view, and a large area can be secured as the core on the yoke 35. This embodiment can also easily accommodate changes in the circumferential size of the core 51E.

Although various embodiments of the first aspect have been described above, the embodiments of the first aspect are not limited thereto. In each of the above embodiments, there are two attachment parts, but three or more attachment parts may be provided. In the case of three, for example, a new attachment part may be provided between the attachment parts 81 and 82, and a fitting part may be added to the corresponding part of the core. Further, the fitting portion may be formed by post-processing a rectangular parallelepiped core formed by laminating rectangular electromagnetic steel plates having the same shape. During post-processing, the laminated electromagnetic steel sheets may be fixed with a jig or the like. In this case, there is a high degree of freedom in the shape and arrangement of the fitting portion.

B. Second aspect:
(8) Second embodiment:
Next, the configuration of the axial gap motor 20 of the second embodiment will be described using FIG. 13 and subsequent figures. The second embodiment and other embodiments are collectively referred to as a second aspect. In the first aspect described above, the attachment parts 81, 82, etc. are both provided across the width direction of the yoke 35, and the plurality of attachment parts are provided apart from each other in the circumferential direction of the yoke 35. On the other hand, in the second embodiment, as shown in FIG. 13, the two mounting portions 91 and 92 are located at the innermost end of the yoke 35 and at the outermost end. It is provided at the outer circumferential end. The lengths of the mounting portions 91 and 92 in the circumferential direction are the same in the second embodiment.

The stator 31F of the second embodiment includes a yoke 35 equipped with attachment parts 91 and 92 at locations corresponding to a plurality of cores 51F, a plurality of cores 51F attached to this yoke 35, and a plurality of cores 51F attached to each core 51F. It also includes a coil (not shown). The installation of the coil is the same as that described in the first embodiment (see FIGS. 4 and 5).

The core 51F of this embodiment has a similar shape to the core 51 of the first embodiment. That is, it has a configuration in which electromagnetic steel sheets 76 are laminated, each having fitting portions 77 and 78 projecting downward on both sides of the lower end. The spacing between the fitting portions 77 and 78 is equal to the spacing between the mounting portions 91 and 92. The fitting portion 77 is provided corresponding to the inner position of the yoke 35 in the radial direction, and the fitting portion 78 is provided corresponding to the outer position of the yoke 35. That is, the fitting parts 77 and 78 are lined up in the radial direction R of the yoke 35. The width of the fitting parts 77 and 78 is equal to the circumferential width of the mounting parts 91 and 92 on the yoke 35 side. Therefore, when the core 51F is attached by fitting the fitting parts 77, 78 into the mounting parts 91, 92 of the yoke 35, the core 51F is arranged across the width direction of the yoke 35, as shown in FIG. . FIG. 15 is a plan view of the core 51F with the yoke 35 attached. In this case, as shown in FIG. 15, all of the stacked electromagnetic steel sheets 76 can have the same shape.

According to the second embodiment described above, in the axial gap motor 20, the two fitting parts 77 and 78 of the core 51F are fixed by the two mounting parts 91 and 92 of the yoke 35, so that the rotor 40 can be rotated. Even if a torque reaction force due to the magnetic flux is applied to the core 51F in the circumferential direction C, the possibility that the core 51F will come off the yoke 35 or be damaged by shear force can be reduced. Furthermore, as shown in FIG. 14, the core 51F of this embodiment can easily be shaped to cover the entire range of the yoke 35 in the width direction, and as a result, the core 51F has a large area relative to the yoke 35. can do. If the core can be made larger, the output of the motor can generally be larger than that of a smaller core. Note that if the shape of the electromagnetic steel plate 76 is such that there are parts projecting outward from the fitting parts 77 and 78 like the electromagnetic steel plate 723 shown in FIG. Furthermore, it is also possible to make the core shape larger.

Furthermore, in this embodiment, the electromagnetic steel plates 76 constituting the core 51F can have the same shape, making it possible to easily manufacture the core 51F. In this embodiment, the core 51F can be attached to the yoke 35 by simply inserting the plurality of fitting portions 77 and 78 into the attachment portions 91 and 92. In this respect, manufacturing of the axial gap motor 20 is facilitated. ing.

(9) Other embodiment 7:
FIG. 16 shows the configuration of a stator 31G according to another embodiment 7. This stator 31G has a configuration in which a core 51G is attached to a yoke 35 having the same shape as the second embodiment. This core 51G has a trapezoidal shape in plan view. In other words, the core 51G of the seventh embodiment has a structure in which the same electromagnetic steel plates 76 as the core 51F of the second embodiment are laminated, and a plurality of electromagnetic steel plates 761, 762, etc. whose widths gradually decrease are laminated on both sides. In this embodiment, a plurality of electromagnetic steel plates 761, 762, etc. whose widths gradually decrease are welded to an electromagnetic steel plate 76 and are integrated.

The stator 31G of the seventh embodiment has the same function and effect as the stator 31F of the second embodiment when attached to the yoke 35, and the area of the core 51G in a plan view can be increased. The magnetic force can be increased by energizing a coil (not shown) provided in the magnetic field. In the example shown in FIG. 16, the mounting part 91 and the mounting part 92 on the yoke 35 side have the same circumferential length, but the circumferential length of the mounting part 92 is made longer, and one side of the electromagnetic steel plates 761, 762, etc. Alternatively, a fitting portion 78 may be formed to fit into the mounting portion 92. In this case, the fixation of the core 51G becomes stronger.

(10) Other embodiment 8:
FIG. 17 shows a main part of a stator 31H according to still another embodiment 8. The stator 31H includes a core 51H as well as a yoke 35 having mounting portions 91 and 92 having the same configuration as the second embodiment and the seventh embodiment. In the core 51H, the stacking direction of the electromagnetic steel sheets is different from the second embodiment and the other embodiment 7, and is in the radial direction R of the yoke 35. The core 51H is constructed by laminating two types of rectangular electromagnetic steel sheets with different heights. That is, the core 51H has a structure in which a plurality of electromagnetic steel plates 772 are laminated, and a plurality of electromagnetic steel plates 771, which are taller than the electromagnetic steel plates 772, are laminated on both sides. At this time, since the upper sides of the electromagnetic steel plate 771 and the electromagnetic steel plate 772 are aligned, the lower ends of the electromagnetic steel plate 771 each protrude below the core 51H, forming a fitting portion 77A. The core 51H is attached to the yoke 35 by fitting the fitting portion 77A into the attachment portions 91 and 92.

In this embodiment 8 as well, like the second embodiment and the other embodiment 7, the core 51H is attached to the yoke 35 at a plurality of locations, and exhibits high strength against the shear force applied to the core 51H.

(11) Other embodiment 9:
FIG. 18 shows a configuration of a stator 31I according to a ninth embodiment, which is similar to the eighth embodiment. In this embodiment 9, a core 51I that constitutes a stator 31I has a trapezoidal shape in plan view. Therefore, the stacked electromagnetic steel sheets all have different sizes. An electromagnetic steel plate 781 that forms a fitting part at the inner circumferential end of the yoke 35 of the electromagnetic steel plates 782 stacked at the center and has a larger height than the electromagnetic steel plates 782 is stacked. Moreover, an electromagnetic steel plate 783 that forms a fitting part at the outer peripheral side end of the yoke 35 of the stacked electromagnetic steel plates 782 and has a larger height than the electromagnetic steel plate 782 is laminated. All the electromagnetic steel plates have a shape in which the length along the circumferential direction C of the yoke 35 gradually increases from the inner circumferential side to the outer circumferential side of the yoke 35.

Therefore, the length along the circumferential direction C of the mounting portions 91A and 92A provided on the yoke 35 is on the radially outer side, that is, on the outer circumferential side, and the length along the circumferential direction C is on the radially inner side, that is, on the inner circumferential side. It is longer than the length of the mounting portion 91A. The stator 31I having such a configuration not only achieves the same effects as the other embodiment 8, but also can increase the area of the core 51I in plan view, and can increase the output of the axial gap motor 20.

(12) Other embodiment 10:
Next, the configuration of a stator 31J according to another embodiment 10 will be described using FIG. 19. In Embodiment 10, a core 51J constituting a stator 31J is formed by laminating electromagnetic steel plates of the same shape along the circumferential direction C to realize a core having a substantially trapezoidal shape in plan view. The yoke 35 has a shape in which the outer peripheral side mounting portion 92B is longer in length along the circumferential direction C than the inner peripheral side mounting portion 91B, similarly to the other embodiment 9.

On the other hand, all the electromagnetic steel plates 79 forming the core 51J have the same shape. That is, the electromagnetic steel plate 79 is provided with fitting portions 77B and 78B at both ends thereof, and is attached to the yoke 35 in a stacked state. As shown at the right end in the lower part of FIG. 18, the electromagnetic steel plate 79 has a thickness d1 on the inner circumferential side smaller than a thickness d2 on the outer circumferential side. Therefore, when a plurality of electromagnetic steel sheets 79 are stacked, the entire core 51J has a trapezoidal shape in plan view. In this state, the relationship between the fitting parts 77B, 78B of the core 51J and the mounting parts 91B, 92B of the yoke is the same as in the other embodiments shown in FIG. 79 have the same shape, and all the electromagnetic steel plates 79 are fitted into the fitting parts 91B, 92B at the fitting parts 77B, 78B, which contributes to increasing the strength.

Of course, by using the electromagnetic steel sheets 79 having this shape, it is also possible to stack them so that both the outer and inner circumferential sides form part of an arc. In this case, since the fitting portions 77B and 78B also have an arc shape, the mounting portions 91B and 92B may also have an arc shape. The electromagnetic steel sheet 79, which has different thicknesses on the inner and outer circumferential sides, can be easily manufactured by passing the electromagnetic steel sheet through rolling rollers with different axial loads before punching the electromagnetic steel sheet with a press. I can do it.

Although various embodiments of the second aspect have been described above, the embodiments of the second aspect are not limited thereto. In each of the above embodiments, the attachment parts 91 and 92 are provided as recesses at the innermost and outermost peripheries of the yoke 35, but they are provided as openings inside the yoke from the innermost and outermost positions of the yoke 35. Good too. In this case, the electromagnetic steel plate forming the core 51F is provided with fitting parts 77, 78, etc. not at both ends of the core 51F, but at positions inside from both ends, like the electromagnetic steel plate 723 shown in FIG. The core 51F may be formed by laminating the above. Further, there may be a plurality of attachment portions, for example, three or more attachment portions may be provided. In the case of three, a new mounting part may be provided between the mounting parts 91 and 92, and a fitting part may be added to the corresponding part of the core. Further, the fitting portion may be formed by post-processing a rectangular parallelepiped core formed by laminating rectangular electromagnetic steel plates having the same shape. During post-processing, the laminated electromagnetic steel sheets may be fixed with a jig or the like. In this case, there is a high degree of freedom in the shape and arrangement of the fitting portion.

C. Other aspects:
The above-described first aspect and second aspect correspond to the difference in the arrangement direction of the attachment part, but this division is for convenience; for example, the attachment part 81 in the first aspect, 82 may be arranged obliquely, such as at 45 degrees, with respect to the direction along the radial direction R of the yoke 35. Alternatively, the mounting portions 85 and 86 shown in FIG. 6C may be substantially circular or rectangular openings, and may be arranged to be shifted in the radial direction, and a corresponding fitting portion may be formed on the core side. Further, the shape of each of the plurality of fitting portions is not limited to a rectangle, but may be a T-shape, a cross-shape, an H-shape, or an arc shape. Furthermore, the shapes of the plurality of fitting portions may be different from each other. The same applies to the mounting portion.

The cores used in each of the above embodiments include cores made by laminating electromagnetic steel plates of the same shape and cores made by laminating electromagnetic steel plates of different shapes. The former requires only one type of electromagnetic steel sheet and is easy to manufacture. On the other hand, the latter has a high degree of freedom in shape because it combines electrical steel sheets with a plurality of shapes. Note that although one type of electromagnetic steel plate may be used in terms of thickness and material, the core may be formed by mixing two or more types of electromagnetic steel plates.

In the above-described axial gap motor 20, the core and yoke constituting each stator are both made of electromagnetic steel sheets, but the lamination direction of the electromagnetic steel sheets in the core and yoke may be in any direction. As shown in FIG. 20, the stacking direction of the electromagnetic steel plates in the yoke 35 may be along the axial direction A of the axial gap motor 20. This lamination direction is preferable because of the direction of the magnetic flux passing through the inside of the yoke 35 and the ease of configuring the yoke 35. On the other hand, it is preferable that the lamination direction of the electromagnetic steel sheets forming the core is other than the direction along the axial direction A.

Typical stacking directions are shown in FIGS. 21 and 22 using cores 51C and 51E. In the core 51C illustrated in FIG. 21, the electromagnetic steel plates are laminated in the direction along the radial direction R. Further, in the core 51E illustrated in FIG. 22, the electromagnetic steel plates are laminated in the direction along the circumferential direction C. In either of the stacking directions shown in FIGS. 21 and 22, the magnetic flux formed by the coil 61 easily passes through the cores 51C and 51E, and loss due to eddy current is reduced.

D. How to manufacture axial gap motor:
A method of manufacturing such an axial gap motor 20 will be briefly described. The axial gap motor 20 is generally manufactured as a motor equipped with an M-phase winding (M is an odd number of 3 or more). In the case of a three-phase, four-pole axial gap motor 20, the number of cores is 12, and the manufacturing process of the axial gap motor 20 is as follows.
[1] The core 51, which is attached to the yoke 35 and has a plurality of fitting parts 72, 73, etc. at different positions on the side facing the yoke 35, is made of a thin plate through which magnetic flux can pass, for example. Step T1 of laminating and forming electromagnetic steel sheets 71;
[2] Step T1 of preparing at least 12 cores 51, etc.;
[3] Step T3 of preparing the yoke 35 including a plurality of attachment parts 81, 82, etc. corresponding to the plurality of fitting parts 72, 73, etc. at each of the positions where the 12 cores 51, etc. are fixed;
[4] A step of assembling the stator 31 etc. including the yoke 35 and the core 51 etc. by fitting the fitting parts 72, 73 of the 12 cores 51 etc. into the attachment parts 81, 82 etc. of the yoke 35, respectively. T4,
[5] Step T5 of attaching the field coil 61 to each of the 12 cores 51 etc. before or after assembling the stator 31 etc.;
[6] The rotor 40, the stator 31, etc., which are rotatably supported, are arranged so that the end surface of the core 51, etc. on the opposite side to the yoke 35 has a gap of a predetermined distance with respect to the rotor 40 in a direction parallel to the axis of rotation A. Step T6 of assembling at a position that is separated by.
Through the above steps, the axial gap motor 20 is manufactured. Note that the order of steps T1 and T2 may be simultaneous or reversed.

According to this manufacturing method, even if a force along the circumferential direction of the yoke 35 is applied to the core 51 etc. as a reaction force of the output torque of the motor by energizing the coil, the axial gap motor can withstand this shear force. 20 can be easily manufactured.

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the spirit thereof. For example, the rotor may have a single stator structure with a stator on one side in the axial direction. It is also possible to adopt a configuration in which the shaft is a fixed shaft, the rotor and the stator are arranged in reverse, and the outer rotates around the fixed shaft. Furthermore, the technical features in the embodiments corresponding to the technical features in each form described in the column of the summary of the invention may be used to solve some or all of the above-mentioned problems, or to achieve one of the above-mentioned effects. In order to achieve some or all of the above, it is possible to replace or combine them as appropriate. Further, unless the technical feature is described as essential in this specification, it can be deleted as appropriate.

20... Axial gap motor, 21... Rotating shaft, 27... Side case, 31, 31C to 31J, 32... Stator, 35, 36... Yoke, 40... Rotor, 41, 43... Permanent magnet, 45... Fixed part, 51, 51A to 51J, 51a, 52... Core, 61, 63... Coil, 71, 76, 79... Electromagnetic steel plate, 72, 72A to 72G... Fitting part, 77, 77A, 77B, 78... Fitting part, 81 to 85 , 81C, 91, 92, 92A, 92B...Mounting part, 711-783...Electromagnetic steel plate

Claims (9)

a rotating rotor and
a stator facing the rotor and disposed with a gap in a first direction parallel to the axis of rotation;
Equipped with
The stator has a core in which thin plates through which magnetic flux passes are laminated along a second direction perpendicular to the first direction, and an annular yoke having the core,
The core has a plurality of independent fitting portions at separated positions, and the plurality of fitting portions for each core include a plurality of fitting portions formed on the yoke itself corresponding to the plurality of fitting portions. It is stuck in the mounting part,
Axial gap motor. The axial gap motor according to claim 1, wherein the plurality of fitting portions are arranged in a circumferential direction of the yoke. The axial gap motor according to claim 1, wherein the plurality of fitting portions are arranged in a radial direction of the yoke. The axial gap motor according to any one of claims 1 to 3, wherein the direction of the lamination of the core is a radial direction of the yoke. The axial gap motor according to any one of claims 1 to 3, wherein the direction of the lamination of the core is a circumferential direction of the yoke. 6. The axial gap motor according to claim 5, wherein the laminated thin plates have a thickness greater at an outer peripheral end of the yoke than at an inner peripheral end of the yoke. The axial gap motor according to any one of claims 1 to 6, wherein the core is formed by laminating the thin plates having the same shape. The axial gap motor according to any one of claims 1 to 6, wherein the core is laminated including the thin plates of different shapes. The thin plate is an electromagnetic steel plate with an insulating layer on the surface,
The core in which the thin plates are laminated has a shape in which a circumferential length of the yoke on the radially outer side of the yoke is larger than a circumferential length of the yoke on the radially inner side of the yoke.
The axial gap motor according to any one of claims 1 to 8.

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